title: Impact of iron-based nanoparticles on microbial denitrification by Paracoccus sp. strain YF1.
abstract: This study investigates the effects of Fe and Fe/Ni nanoparticles on biological denitrification when using Paracoccus sp. strain YF1. Results show that adding Fe and Fe/Ni nanoparticles to the cells decreased their growth and denitrification rate. Compared to that of free cells (control 89.47%), a decrease (64.33%) in the presence of 1000 mg/L Fe/Ni nanoparticles was observed, while a small decline in the denitrification rate (76.36%) was obtained when the concentration of Fe nanoparticles was 1000 mg/L. These were further confirmed by adding Fe(2+), Fe(3+), Fe3O4, Fe(2+)/Ni(2+) and Fe(3+)/Ni(2+) individually to the free cell system. Furthermore, Fe and Fe/Ni nanoparticles influenced the nitrate removal and bacterial growth under different pH and temperature conditions. SEM, XRD and EDS demonstrated that iron oxides formed as a result of nanoparticles corrosion in biological medium. Finally the presence of nanoparticles around some bacteria was observed.
authors.affiliation: School of Life Science, Fujian Normal University, Fuzhou 350108, China.
authors.forename: Chenghong
authors.initials: C
authors.lastname: Jiang
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.forename: Zuliang
authors.initials: Z
authors.lastname: Chen
authors.forename: Mallavarapu
authors.initials: M
authors.lastname: Megharaj
authors.forename: Ravendra
authors.initials: R
authors.lastname: Naidu
mesh_terms: D058440:Denitrification / Q000187:drug effects*; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000633:toxicity*; D053768:Metal Nanoparticles / Q000633:toxicity*; D009566:Nitrates / Q000378:metabolism; D010230:Paracoccus / Q000187:drug effects* / Q000254:growth & development; D013696:Temperature; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D009566:Nitrates; D014874:Water Pollutants, Chemical; D007501:Iron
keywords: Cell growth; Denitrification; Nanoparticles; Paracoccus sp. YF1